The present invention relates to venturi type mixing of gas and liquids, and more particularly concerns such type of mixing that produces a pulsating discharge of the mixture.
In spas, therapy pools, swimming pools and similar apparatus, jets of water are projected into the body of water contained in the spa, pool or tub to provide a type of hydromassage, enhanced relaxation and other therapeutic benefits. To increase the action, force and benefit of such jets, the water, before projection, is mixed with air by means of air/water mixers that commonly employ a venturi type action. An increased velocity jet projected into a mixing chamber provides an area of reduced pressure that pulls air into the chamber through a passage that communicates with ambient atmosphere. The air pulled into the chamber mixes with the water and the mixture is discharged through a nozzle into (below the surface of) the body of water contained in the spa or pool tub. Venturi type mixers for spas, therapy pools and the like are typified by those shown in the U.S. Pat. Nos. to Baker 3,471,091; Steimle 3,628,529; Jacuzzi 3,905,358; Mathis 3,890,655; and Mathis 3,890,656. Another type of such a venturi type jet is shown in the co-pending application of Gerald Moreland, Ser. No. 040,589, filed May 21, 1979, now U.S. Pat. No. 4,264,039, entitled AERATOR.
The enhanced massaging and therapeutic actions of pulsating nonaerated water jets are well known and typical devices for providing such water pulsations (without air entrainment) are shown in the U.S. Pat. Nos. to Erwin 2,878,066; Donovan 1,446,887; Heitzman 3,473,736, and Heitzman 4,101,075. Pulsed water jets of the prior art have either repetitively diverted the water flow from the desired outlet or repetitively stopped water flow into the water outlet. Prior efforts to provide a pulsed air/water mixer have merely followed principles used in pulsation of nonaerated water streams and employed devices to either stop or divert the water flow before it enters the mixing chamber.
Devices that totally obstruct the water flow can cause abrupt pressure increases and noise, imposing severe strains upon the system. Devices attempting to control air flow have generally required external controlling mechanisms and thus become less efficient, more complex, and more costly.
Accordingly, it is an object of the present invention to provide a pulsed air/water mixer that avoids or eliminates above-mentioned problems and limitations of prior devices.